EXAM 1 Flashcards
classifications
Kingdoms: ANIMALIA, fungi, protista, plantae, bacteria, archaea
Phyla: CHORDATA, arthropoda, cnideria, echinodermata
Subphylum: VERTEBRATA, cephalocordata, urochordata
Class: MAMMALIA, aves and reptilia, amphibia, osteichthyes (bony fish), chondrichthyes (cartil. fish)
sister group and ougroup
sister: most closely related (echinoderms and chordates)
outgroup: group least like others (echinoderms)
chordates
have/had notochord (cartilaginous rod, can become spine)
dorsal hollow nerve cord (becomes spinal cord)
pharyngeal slits (gas exchange, gills or pharynx)
post anal tail
clade
monophyletic group
includes all descendants of common ancestor
determined by nodes
basal
first group
basal vertebrate is pikaia
basal jaw is placoderm
subphylum chordata
cephalochordate - amphioxus
urochordate - tunicate or sea squirt (colonial, green blood, cellulose, adults lose all chordate features)
vertebrate - all have exoskeleton
synapomorphy
new characteristics shared later
jawless vertebrates
hagfish, lamprey
have spine, no jaw –> secondary loss
cyclostomes or agnathans
gnathostomes
jawed fish
placoderm = jaw origination, armored bony fish
permian extinction
250 mya
lava flows, greenhouse gases
most of ocean and land life killed (kills synapsids, opens spot for dinos)
KT extinction kills dinos –> mammal diversity
leads to mammal diversity
cambrian explosion
oxygen allows diversification of body plan
pikaia
first living thing to leave water: fungus, then plants, worms, arthro, vert
tetrapods
4 footed
amphibia, reptilia, mammalia
tiktaalik = transitional fossil from water to land
homologous structures in fin and hand
amniotic egg development for land
extra embryonic membranes = protect, supply gases, and feed
longer development –> better protection
amphibians are between aquatic and terrestrial
big AR after tetrapods leave water
homologous structure
originate from ancestor
fin and hand
synapsid
1 temporal fenestra
mammals
before dinos –> extinct after permian –> disaster taxa lystrosaurus mammal ancestor and AR
diapsid
2 temporal fenestra
early reptiles
anapsid
no temporal fenestra
turtles
synapsid hearing
from jaw evolution
early synapsid moves only lower jaw (dentary and angular)
dentary turns into lower jaw
guadrate articular becomes squamosal dentary
guadrate becomes incus (ear)
articular becomes middle ear malleus
reptiles only have stapes –> jaw transformed 2 bones for hearing
mammals need better hearing because of nocturnal
amniote
reptiles/birds
mammals
not all tetrapods are amniotes
anapsid, synapsid, diapsid
glands
epidermal produce material to secrete sweat, oil, poison, mucus aquatic unicellular sebaceous = oil eccrine and apocrine = sweat poison glands in all amphibians (dendrobatidae)
epithelial tissue
makes up epidermis
epidermis
very tight cells
avascular (except in amphibians)
protects
2 epidermis coverings: mucus (fish) and keratinized cells
nuclei degenerate towards superficial
stratum corneum (superficial) and basal layer (deep)
stratum corneum
superficial dead layer epidermis
shedding without energy
basal layer
deepest layer epidermis
lies on basement membrane
keratin
protein that hardens the cell and makes it waterproof
epidermis stratum corneum
keratin teeth (lamprey/hagfish), nails, hair
produced by keratinocytes
sweat glands
eccrine
apocrine - signalling/pheromones
aposematic coloring
warning color
epidermal gland
epidermal structures
hair (only in mammals)
feathers
nails, hoofs, horns, claws
feathers
epidermal
nonliving, avascular, keratin
hooks allow constant surface
protofeathers = single filament (dino)
more complex feathers existed with protofeathers
feather development from epidermis invagination
purpose: thermoregulation and signalling
melanocytes
endotherms (birds/mammals)
epidermal pigment
deposit melanin to cells in basal layer
melanophores
ectotherms (reptiles, fish, amphibians)
epidermal pigment
melanin
created by melanocytes
moves with nuclear degradation to stratum corneus
granule size, amount, position determine color
nuclear cap = granules protect nucleus from UV radiation
feather color
pigment and structure interaction
pigment = chemical that absorbs and reflects waves (melanin)
structure = crystal structures that refract light (keratin)
black/brown is just melanin
blue is melanin interaction with keratin spongy layer
iridescence from pigment and structure interaction
color in barbules, not dermis or barbs
can only change with molting
iridescence controlled by melanin shape (rods/platelets) or hollowness in barbules
pigments
melanin - blacks browns, in tips of feathers for strength
carotenoids - yellow orange from diet
contour feathers
body feathers
alulua
tiny feather to keep air smooth
melanosome
packets of melanin
fossilized feathers and skin show melanin packing in melanosomes - color deduction
dermis
sits on top of fat
vascular, alive
thicker than epidermis
matrix
collagen and elastin = connective tissue providing flexibility
can form dermal bone (turtles, crocodiles, armadillos, extinct fish - ostracoderms and placoderms)
ectotherm pigment and metachrosis
ostracoderms
jawless fish with headshield
dermal bone
placoderm
jaw fish with bony head place
dermal bone
fish scales
dermal bone
ctenoid (perch), cycloid, ganoid, placoid (dogfish or chondricthyes)
placoid scales homologous with teeth, have enameloid epidermal cover, pulp cavity and dentin are dermal
bony fish scales covered in non keratinized epidermal layer protected by mucus
dermal color
ectotherms
chromatophores produce pigments
chromatophores
produce pigments erythrophore - red xanthophore - yellow iridophore - reflective melanophore - black/brown melanophore dispersion into upper layers makes darker colors
metachrosis
rapid pigment change
peacock flounder and chameleon
photonic crystal interacts with pigments
photonic crystals
dermal metachrosis structural organization that refracts light structural blue in feathers crystal spacing changes color larger spacing is relaxed - green sexual dimorphism
peacock flounder
fish that lives on lateral surface eye migrates to lateral side uses color change for predator + prey matches sand color and pattern only melanin
scale evolution
lobe finned fish –> lose scales (friction, thermo) –> tiktaalik –> tetrapods
tetrapods (amphibians) –> new scales (epidermal) –> reptiles
birds and reptiles have epidermal scales - sheet with hinge for flexibility and prevent water loss
fish have dermal scales
osteoderm - dermal thickening from dermal scales in epidermal scales
bone formation
intramembranous ossification
endochondral ossification
intramembranous ossification
dermal bone formation
small, simple
flat bones - start of skull, fish scales
direct
endochondral ossification
vascular cartilage scaffolding intermediary most cart. ossified some remain in growth plates and joints long bones and bone majority
mesenchyme
builder cells in animal tissue
complex of loose cells in matrix
give rise to connective tissue
skeleton division
axial - skull, spine, notochord
appendicular - girdle and limbs
cranial - axial
skull purpose
protect brain and sensory
mastication
gill support
air filtering and humidfying
chondrocranium
cartilage part of skull
supports brain/sensory
chondrichtyes
lost in humans - scaffold for dermatocranium in embryo
splanchnocranium
jaw and gill arches
oldest
endochondral ossification
dermatocranium
external sheet
intramembranous ossification
dermal
most of human skull
branchial arches
gill arches
ostracoderm
first “true” fish
jawless
dermal shield
wiped out by mass extinction and jaw evolution
bird skulls
large orbit
no teeth
lightweight skull
shrunken chondrocranium
placoderm
jaw origination first copulatory organ = claspers scissor blade jaw - disappears with placoderm dermal bone teeth appeared during silurian has gnathal plates (first teeth) entelognathus and qilinyu
gnathal plates
dermal bone for cutting
placoderm jaw
beginning of dentary proven by qilinyu
entelognathus
maxillate placoderm with tripartite jaw
first dentary bone
qilinyu
placoderm jaw transition fossil
tripartite jaw
older than entelognathus
jaw evolution
1st branchial arch forms jaw
99% vert have jaws
not from chondricthyes - secondary loss of bone
